Touch pads, which are two-dimensional touch-sensitive surfaces, have been used on computer laptops for controlling the movement of the cursor of the display. Commonly used touch pad configurations include square configurations and non-elongated rectangular configurations. Commercially available touch pads, such as those manufactured by Synaptics Inc., have been provided with software that enables the use of the right or bottom edge of the unitary surface touch pad as a scrolling zone. Such an arrangement is disclosed in U.S. Pat. No. 5,943,052 to Allen et al. However, these touch pad input devices, however, are also used for cursor positioning and thus are not dedicated to scrolling. This can cause problems of erroneous activation for the user. These problems include the activation of scrolling when cursor positioning is desired, and the activation of cursor positioning when scrolling is desired.
A commercially available touch pad made by Synaptics Inc. uses software that discriminates different end zones in a scrolling region of a touch pad. When a finger of a user reaches a longitudinal end of the touch pad in the scroll region, the scrolling will continue until the user moves lifts his or her finger from the touch pad or moves his or her finger away from the edge of the touch pad. However, if the user is concentrating on the display, it may be difficult for the user to maximize the scrolling capabilities as it is difficult to know when and whether his or her finger is in or near such a longitudinal end portion. Accordingly, a user may move his finger to reach or leave the end portion prematurely, or may never reach the end portion believing his or her finger is already located in the end portion.
U.S. Pat. No. 5,748,185 to Stephan et al. discloses a touch pad that is physically divided by a cover to provide a square cursor control region, a vertically elongated rectangular scroll control region, and a horizontally elongated pan control region. These regions are illustrated as being a part of a separate input device (in FIG. 2 of U.S. Pat. No. 5,748,185) or in the region in front of the keyboard portion of a laptop computer (in FIG. 13 of U.S. Pat. No. 5,748,185). Additionally, FIG. 10 of U.S. Pat. No. 5,748,185 discloses a unitary surface with elongated scroll and pan bars that overlap in the shape of a “plus” (+). The region where the horizontal pan control bar crosses the vertical scroll control bar overlap is not mapped to control either panning or scrolling. Such an unmapped region would appear to be detrimental in maximizing panning and scrolling control when the user runs his or her finger along the horizontal or vertical bar in the desired direction.
Further, U.S. Pat. No. 6,043,809 to Holehan discloses in FIGS. 1 and 2 the use of a touch sensitive input scroll bars on three edge surfaces of a laptop computer, and on three edge surfaces, between distinct alphanumeric and editing sections, and between distinct editing and numeric sections on a keyboard. However, one potential drawback of these arrangements is that edge regions and the regions between distinct keyboard input sections (such as between distinct alphanumeric and editing sections, and between distinct editing and numeric sections) are sometimes used as resting places for portions of the hands of the user. An occurrence of such an incidental resting on an input scroll bar can cause unintended scrolling for the document on the display.
Additionally, the longitudinal ends of the scroll and panning control regions for all of these arrangements terminate abruptly with a flat edge. This makes it difficult for the user to efficiently recognize when her or she is approaching the end of the region as the user is normally focusing on the document on the display. This also has some drawbacks in the ability to maximize scrolling control, which can be more significant when software provides the end portions with different scrolling capabilities. Accordingly, a solution to this problem is needed.